refactor(engine): split settings_plugin runtime code into submodules

Second phase of #118 for settings_plugin: the 2,857-line mod.rs becomes four focused submodules along existing system boundaries — mod.rs 561 types, markers, SettingsButton, plugin build, persistence input.rs 632 button/hotkey handlers, focus attachment, scrolling updates.rs 495 per-frame value-text updater systems + label helpers ui.rs 1,231 spawn_settings_panel + row builders + thumbnails Moved items are pub(super); mod.rs glob-imports the submodules so system registration and tests keep their bare names. No behaviour change; all 29 settings tests pass unchanged. Refs #118 Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-06 13:45:57 -07:00
parent 8274581edf
commit 1ca1efb3b6
5 changed files with 2367 additions and 2314 deletions
@@ -0,0 +1,627 @@
+//! Input handling for the Settings panel: button presses, keyboard
+//! accelerators, focus attachment, and scrolling.
+
+use super::*;
+
+use bevy::input::mouse::{MouseScrollUnit, MouseWheel};
+use bevy::ui::{ComputedNode, UiGlobalTransform};
+use solitaire_core::DrawStockConfig;
+use solitaire_data::{
+    AnimSpeed, REPLAY_MOVE_INTERVAL_STEP_SECS, TIME_BONUS_MULTIPLIER_STEP, TOOLTIP_DELAY_STEP_SECS,
+    settings::Theme,
+};
+
+use crate::events::{
+    DeleteAccountRequestEvent, InfoToastEvent, ManualSyncRequestEvent, SyncConfigureRequestEvent,
+    SyncLogoutRequestEvent, ToggleSettingsRequestEvent,
+};
+use crate::ui_focus::{FocusGroup, Focusable, FocusedButton};
+use crate::ui_modal::{ModalButton, ModalScrim};
+use crate::ui_theme::SPACE_2;
+
+pub(super) fn handle_volume_keys(
+    keys: Res<ButtonInput<KeyCode>>,
+    mut settings: ResMut<SettingsResource>,
+    path: Res<SettingsStoragePath>,
+    mut changed: MessageWriter<SettingsChangedEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
+) {
+    let mut delta = 0.0_f32;
+    if keys.just_pressed(KeyCode::BracketLeft) {
+        delta -= SFX_STEP;
+    }
+    if keys.just_pressed(KeyCode::BracketRight) {
+        delta += SFX_STEP;
+    }
+    if delta == 0.0 {
+        return;
+    }
+    let before = settings.0.sfx_volume;
+    let after = settings.0.adjust_sfx_volume(delta);
+    if (before - after).abs() < f32::EPSILON {
+        return;
+    }
+    persist(&path, &settings.0);
+    changed.write(SettingsChangedEvent(settings.0.clone()));
+    toast.write(InfoToastEvent(format!(
+        "SFX volume: {}%",
+        (after * 100.0).round() as i32
+    )));
+}
+
+/// Opens or closes the Settings panel — `O` keyboard accelerator or
+/// `ToggleSettingsRequestEvent` from the HUD Menu popover.
+pub(super) fn toggle_settings_screen(
+    keys: Res<ButtonInput<KeyCode>>,
+    mut requests: MessageReader<ToggleSettingsRequestEvent>,
+    mut screen: ResMut<SettingsScreen>,
+) {
+    let button_clicked = requests.read().count() > 0;
+    if keys.just_pressed(KeyCode::KeyO) || button_clicked {
+        screen.0 = !screen.0;
+    }
+}
+
+/// Reacts to button presses inside the Settings panel.
+#[allow(clippy::too_many_arguments, clippy::type_complexity)]
+pub(super) fn handle_settings_buttons(
+    interaction_query: Query<(&Interaction, &SettingsButton), Changed<Interaction>>,
+    mut settings: ResMut<SettingsResource>,
+    mut screen: ResMut<SettingsScreen>,
+    path: Res<SettingsStoragePath>,
+    mut changed: MessageWriter<SettingsChangedEvent>,
+    mut sfx_text: Query<
+        &mut Text,
+        (
+            With<SfxVolumeText>,
+            Without<MusicVolumeText>,
+            Without<DrawModeText>,
+            Without<ThemeText>,
+            Without<AnimSpeedText>,
+            Without<ColorBlindText>,
+            Without<HighContrastText>,
+            Without<ReduceMotionText>,
+        ),
+    >,
+    mut music_text: Query<
+        &mut Text,
+        (
+            With<MusicVolumeText>,
+            Without<SfxVolumeText>,
+            Without<DrawModeText>,
+            Without<ThemeText>,
+            Without<AnimSpeedText>,
+            Without<ColorBlindText>,
+            Without<HighContrastText>,
+            Without<ReduceMotionText>,
+        ),
+    >,
+    mut draw_text: Query<
+        &mut Text,
+        (
+            With<DrawModeText>,
+            Without<SfxVolumeText>,
+            Without<MusicVolumeText>,
+            Without<ThemeText>,
+            Without<AnimSpeedText>,
+            Without<ColorBlindText>,
+            Without<HighContrastText>,
+            Without<ReduceMotionText>,
+        ),
+    >,
+    mut theme_text: Query<
+        &mut Text,
+        (
+            With<ThemeText>,
+            Without<SfxVolumeText>,
+            Without<MusicVolumeText>,
+            Without<DrawModeText>,
+            Without<AnimSpeedText>,
+            Without<ColorBlindText>,
+            Without<HighContrastText>,
+            Without<ReduceMotionText>,
+        ),
+    >,
+    mut anim_speed_text: Query<
+        &mut Text,
+        (
+            With<AnimSpeedText>,
+            Without<SfxVolumeText>,
+            Without<MusicVolumeText>,
+            Without<DrawModeText>,
+            Without<ThemeText>,
+            Without<ColorBlindText>,
+            Without<HighContrastText>,
+            Without<ReduceMotionText>,
+        ),
+    >,
+    mut color_blind_text: Query<
+        &mut Text,
+        (
+            With<ColorBlindText>,
+            Without<SfxVolumeText>,
+            Without<MusicVolumeText>,
+            Without<DrawModeText>,
+            Without<ThemeText>,
+            Without<AnimSpeedText>,
+            Without<HighContrastText>,
+            Without<ReduceMotionText>,
+        ),
+    >,
+    mut high_contrast_text: Query<
+        &mut Text,
+        (
+            With<HighContrastText>,
+            Without<SfxVolumeText>,
+            Without<MusicVolumeText>,
+            Without<DrawModeText>,
+            Without<ThemeText>,
+            Without<AnimSpeedText>,
+            Without<ColorBlindText>,
+            Without<ReduceMotionText>,
+        ),
+    >,
+    mut reduce_motion_text: Query<
+        &mut Text,
+        (
+            With<ReduceMotionText>,
+            Without<SfxVolumeText>,
+            Without<MusicVolumeText>,
+            Without<DrawModeText>,
+            Without<ThemeText>,
+            Without<AnimSpeedText>,
+            Without<ColorBlindText>,
+            Without<HighContrastText>,
+        ),
+    >,
+) {
+    for (interaction, button) in &interaction_query {
+        if *interaction != Interaction::Pressed {
+            continue;
+        }
+        match button {
+            SettingsButton::SfxDown => {
+                let before = settings.0.sfx_volume;
+                let after = settings.0.adjust_sfx_volume(-SFX_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    if let Ok(mut t) = sfx_text.single_mut() {
+                        **t = format!("{after:.2}");
+                    }
+                }
+            }
+            SettingsButton::SfxUp => {
+                let before = settings.0.sfx_volume;
+                let after = settings.0.adjust_sfx_volume(SFX_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    if let Ok(mut t) = sfx_text.single_mut() {
+                        **t = format!("{after:.2}");
+                    }
+                }
+            }
+            SettingsButton::MusicDown => {
+                let before = settings.0.music_volume;
+                let after = settings.0.adjust_music_volume(-SFX_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    if let Ok(mut t) = music_text.single_mut() {
+                        **t = format!("{after:.2}");
+                    }
+                }
+            }
+            SettingsButton::MusicUp => {
+                let before = settings.0.music_volume;
+                let after = settings.0.adjust_music_volume(SFX_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    if let Ok(mut t) = music_text.single_mut() {
+                        **t = format!("{after:.2}");
+                    }
+                }
+            }
+            SettingsButton::ToggleDrawMode => {
+                settings.0.draw_mode = match settings.0.draw_mode {
+                    DrawStockConfig::DrawOne => DrawStockConfig::DrawThree,
+                    DrawStockConfig::DrawThree => DrawStockConfig::DrawOne,
+                };
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                if let Ok(mut t) = draw_text.single_mut() {
+                    **t = draw_mode_label(&settings.0.draw_mode);
+                }
+            }
+            SettingsButton::CycleAnimSpeed => {
+                settings.0.animation_speed = match settings.0.animation_speed {
+                    AnimSpeed::Normal => AnimSpeed::Fast,
+                    AnimSpeed::Fast => AnimSpeed::Instant,
+                    AnimSpeed::Instant => AnimSpeed::Normal,
+                };
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                if let Ok(mut t) = anim_speed_text.single_mut() {
+                    **t = anim_speed_label(&settings.0.animation_speed);
+                }
+            }
+            SettingsButton::TooltipDelayDown => {
+                let before = settings.0.tooltip_delay_secs;
+                let after = settings.0.adjust_tooltip_delay(-TOOLTIP_DELAY_STEP_SECS);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    // The Text node is refreshed by `update_tooltip_delay_text`
+                    // on the next frame via `settings.is_changed()`.
+                }
+            }
+            SettingsButton::TooltipDelayUp => {
+                let before = settings.0.tooltip_delay_secs;
+                let after = settings.0.adjust_tooltip_delay(TOOLTIP_DELAY_STEP_SECS);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                }
+            }
+            SettingsButton::TimeBonusDown => {
+                let before = settings.0.time_bonus_multiplier;
+                let after = settings
+                    .0
+                    .adjust_time_bonus_multiplier(-TIME_BONUS_MULTIPLIER_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    // The Text node is refreshed by
+                    // `update_time_bonus_multiplier_text` on the next
+                    // frame via `settings.is_changed()`.
+                }
+            }
+            SettingsButton::TimeBonusUp => {
+                let before = settings.0.time_bonus_multiplier;
+                let after = settings
+                    .0
+                    .adjust_time_bonus_multiplier(TIME_BONUS_MULTIPLIER_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                }
+            }
+            SettingsButton::ReplayMoveIntervalDown => {
+                let before = settings.0.replay_move_interval_secs;
+                let after = settings
+                    .0
+                    .adjust_replay_move_interval(-REPLAY_MOVE_INTERVAL_STEP_SECS);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    // The Text node is refreshed by
+                    // `update_replay_move_interval_text` on the next
+                    // frame via `settings.is_changed()`.
+                }
+            }
+            SettingsButton::ReplayMoveIntervalUp => {
+                let before = settings.0.replay_move_interval_secs;
+                let after = settings
+                    .0
+                    .adjust_replay_move_interval(REPLAY_MOVE_INTERVAL_STEP_SECS);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                }
+            }
+            SettingsButton::ToggleTheme => {
+                settings.0.theme = match settings.0.theme {
+                    Theme::Green => Theme::Blue,
+                    Theme::Blue => Theme::Dark,
+                    Theme::Dark => Theme::Green,
+                };
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                if let Ok(mut t) = theme_text.single_mut() {
+                    **t = theme_label(&settings.0.theme);
+                }
+            }
+            SettingsButton::ToggleColorBlind => {
+                settings.0.color_blind_mode = !settings.0.color_blind_mode;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                if let Ok(mut t) = color_blind_text.single_mut() {
+                    **t = color_blind_label(settings.0.color_blind_mode);
+                }
+            }
+            SettingsButton::ToggleHighContrast => {
+                settings.0.high_contrast_mode = !settings.0.high_contrast_mode;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                if let Ok(mut t) = high_contrast_text.single_mut() {
+                    **t = on_off_label(settings.0.high_contrast_mode);
+                }
+            }
+            SettingsButton::ToggleReduceMotion => {
+                settings.0.reduce_motion_mode = !settings.0.reduce_motion_mode;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                if let Ok(mut t) = reduce_motion_text.single_mut() {
+                    **t = on_off_label(settings.0.reduce_motion_mode);
+                }
+            }
+            SettingsButton::ToggleTouchInputMode => {
+                use solitaire_data::settings::TouchInputMode;
+                settings.0.touch_input_mode = match settings.0.touch_input_mode {
+                    TouchInputMode::OneTap => TouchInputMode::TapToSelect,
+                    TouchInputMode::TapToSelect => TouchInputMode::OneTap,
+                };
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                // Text refreshed by `update_touch_input_mode_text` next frame.
+            }
+            SettingsButton::ToggleWinnableDealsOnly => {
+                settings.0.winnable_deals_only = !settings.0.winnable_deals_only;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                // The Text node is refreshed by `update_winnable_deals_only_text`
+                // on the next frame via `settings.is_changed()`.
+            }
+            SettingsButton::ToggleAnalytics => {
+                settings.0.analytics_enabled = !settings.0.analytics_enabled;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                // Text refreshed by `update_analytics_enabled_text` next frame.
+            }
+            SettingsButton::ToggleSmartDefaultSize => {
+                settings.0.disable_smart_default_size = !settings.0.disable_smart_default_size;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                // The Text node is refreshed by
+                // `update_smart_default_size_text` next frame. The
+                // sizer system is gated only at startup, so flipping
+                // this mid-session takes effect on the next launch —
+                // documented on the field in `solitaire_data::Settings`.
+            }
+            SettingsButton::SelectCardBack(idx) => {
+                settings.0.selected_card_back = *idx;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+            }
+            SettingsButton::SelectBackground(idx) => {
+                settings.0.selected_background = *idx;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+            }
+            SettingsButton::SelectTheme(theme_id) => {
+                if settings.0.selected_theme_id != *theme_id {
+                    settings.0.selected_theme_id = theme_id.clone();
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                }
+            }
+            #[cfg(not(target_arch = "wasm32"))]
+            SettingsButton::ScanThemes => {
+                // Handled by `handle_scan_themes`.
+            }
+            SettingsButton::SyncNow
+            | SettingsButton::ConnectSync
+            | SettingsButton::DisconnectSync
+            | SettingsButton::DeleteAccount => {
+                // Handled by `handle_sync_buttons`.
+            }
+            SettingsButton::Done => {
+                screen.0 = false;
+            }
+        }
+    }
+}
+
+/// Handles sync-related settings buttons: Sync Now, Connect, Disconnect,
+/// and Delete Account. Split from `handle_settings_buttons` to stay within
+/// Bevy's 16-parameter system limit.
+pub(super) fn handle_sync_buttons(
+    interaction_query: Query<(&Interaction, &SettingsButton), Changed<Interaction>>,
+    mut manual_sync: MessageWriter<ManualSyncRequestEvent>,
+    mut configure_sync: MessageWriter<SyncConfigureRequestEvent>,
+    mut logout_sync: MessageWriter<SyncLogoutRequestEvent>,
+    mut delete_account: MessageWriter<DeleteAccountRequestEvent>,
+    mut screen: ResMut<SettingsScreen>,
+) {
+    for (interaction, button) in &interaction_query {
+        if *interaction != Interaction::Pressed {
+            continue;
+        }
+        match button {
+            SettingsButton::SyncNow => {
+                manual_sync.write(ManualSyncRequestEvent);
+            }
+            SettingsButton::ConnectSync => {
+                // Close settings before the sync-setup modal opens so the
+                // guard in open_sync_setup_modal doesn't block on our own scrim.
+                screen.0 = false;
+                configure_sync.write(SyncConfigureRequestEvent);
+            }
+            SettingsButton::DisconnectSync => {
+                logout_sync.write(SyncLogoutRequestEvent);
+            }
+            SettingsButton::DeleteAccount => {
+                delete_account.write(DeleteAccountRequestEvent);
+            }
+            _ => {}
+        }
+    }
+}
+
+/// Auto-attaches [`Focusable`] to every bespoke Settings button — icon
+/// buttons (volume +/−, toggle, cycle), swatch buttons (card-back,
+/// background pickers), and the "Sync Now" button. The "Done" button is
+/// already tagged by `attach_focusable_to_modal_buttons` (it carries
+/// [`ModalButton`]) and is filtered out here.
+///
+/// Walks ancestors via [`ChildOf`] to find the [`ModalScrim`] that owns
+/// the panel so the new [`Focusable`]'s group is bound to that scrim —
+/// same defensive shape as the Phase 1 / 2 attach systems.
+#[allow(clippy::type_complexity)]
+pub(super) fn attach_focusable_to_settings_buttons(
+    mut commands: Commands,
+    new_buttons: Query<
+        (Entity, &SettingsButton),
+        (With<Button>, Without<Focusable>, Without<ModalButton>),
+    >,
+    parents: Query<&ChildOf>,
+    scrims: Query<(), With<ModalScrim>>,
+) {
+    for (button, settings_button) in &new_buttons {
+        let mut current = button;
+        let mut scrim_entity: Option<Entity> = None;
+        for _ in 0..32 {
+            if scrims.get(current).is_ok() {
+                scrim_entity = Some(current);
+                break;
+            }
+            match parents.get(current) {
+                Ok(parent) => current = parent.parent(),
+                Err(_) => break,
+            }
+        }
+        if let Some(scrim) = scrim_entity {
+            commands.entity(button).insert(Focusable {
+                group: FocusGroup::Modal(scrim),
+                order: settings_button.focus_order(),
+            });
+        }
+    }
+}
+
+/// Vertical padding (logical px) added around the focused button when
+/// scrolling it into view. Keeps the focus ring's halo visible above /
+/// below the viewport edge.
+const FOCUS_SCROLL_PADDING: f32 = SPACE_2;
+
+/// When the focused entity sits outside the visible Settings scroll
+/// viewport, adjust the viewport's [`ScrollPosition`] so the button is
+/// fully visible. No-op when:
+///
+/// - `FocusedButton` is `None`
+/// - the focused entity has no [`UiGlobalTransform`] / [`ComputedNode`]
+///   (e.g. a freshly-spawned modal hasn't laid out yet)
+/// - the focused entity is not a descendant of the
+///   [`SettingsPanelScrollable`] container
+///
+/// The viewport's visible Y range is `[scroll_y, scroll_y +
+/// viewport_height]` in physical pixels (matching `ComputedNode.size`).
+/// The focused button's vertical extent is computed from its
+/// `UiGlobalTransform.translation.y` (centre, physical) ± half its
+/// `ComputedNode.size.y`. Because the scroll container's local
+/// coordinates run [0, content_height] and the visible window is
+/// [scroll_y, scroll_y + viewport], we convert the button's window-
+/// space Y to container-local Y by subtracting the container's window-
+/// space top and adding the current scroll offset.
+#[allow(clippy::type_complexity)]
+pub(super) fn scroll_focus_into_view(
+    focused: Res<FocusedButton>,
+    parents: Query<&ChildOf>,
+    nodes: Query<(&UiGlobalTransform, &ComputedNode)>,
+    mut containers: Query<
+        (&mut ScrollPosition, &UiGlobalTransform, &ComputedNode),
+        With<SettingsPanelScrollable>,
+    >,
+) {
+    let Some(target) = focused.0 else { return };
+    // Gather button geometry.
+    let Ok((target_transform, target_node)) = nodes.get(target) else {
+        return;
+    };
+
+    // Walk ancestors looking for the scroll container. Bounded to keep
+    // a malformed hierarchy from hanging the system.
+    let mut current = target;
+    let mut container_entity: Option<Entity> = None;
+    for _ in 0..32 {
+        if containers.get(current).is_ok() {
+            container_entity = Some(current);
+            break;
+        }
+        match parents.get(current) {
+            Ok(parent) => current = parent.parent(),
+            Err(_) => break,
+        }
+    }
+    let Some(container) = container_entity else {
+        return;
+    };
+
+    let Ok((mut scroll, container_transform, container_node)) = containers.get_mut(container)
+    else {
+        return;
+    };
+
+    // Geometry is reported in physical pixels by `ComputedNode.size` and
+    // `UiGlobalTransform.translation`. `ScrollPosition` is in logical px,
+    // so convert via `inverse_scale_factor` before we write.
+    let inv = target_node.inverse_scale_factor;
+    let target_height = target_node.size().y;
+    let target_centre_y = target_transform.translation.y;
+    let target_top = target_centre_y - target_height * 0.5;
+    let target_bottom = target_centre_y + target_height * 0.5;
+
+    let container_height = container_node.size().y;
+    let container_top = container_transform.translation.y - container_height * 0.5;
+
+    // Convert button window-space Y to container-local Y. The container
+    // is currently scrolled by `scroll.0.y` *logical* pixels — multiply
+    // by physical-per-logical to compare with physical pixel extents.
+    let scroll_phys = scroll.0.y / inv.max(f32::EPSILON);
+    let viewport_top = container_top + scroll_phys;
+    let viewport_bottom = viewport_top + container_height;
+
+    // Layout may not have run yet (zero size on first frame) — no
+    // sensible scroll target until the container has dimensions.
+    if container_height <= 0.0 {
+        return;
+    }
+
+    let pad_phys = FOCUS_SCROLL_PADDING / inv.max(f32::EPSILON);
+    if target_top < viewport_top {
+        // Button extends above the viewport — scroll up.
+        let new_top = target_top - pad_phys;
+        let delta = new_top - viewport_top;
+        scroll.0.y = ((scroll_phys + delta) * inv).max(0.0);
+    } else if target_bottom > viewport_bottom {
+        // Button extends below the viewport — scroll down.
+        let new_bottom = target_bottom + pad_phys;
+        let delta = new_bottom - viewport_bottom;
+        scroll.0.y = ((scroll_phys + delta) * inv).max(0.0);
+    }
+}
+
+/// Scrolls the settings panel inner card in response to mouse-wheel events.
+///
+/// `offset_y` increases downward (0 = top of content). Scrolling down (ev.y < 0)
+/// adds to the offset; scrolling up subtracts. Clamped to >= 0 so it never
+/// scrolls past the top.
+pub(super) fn scroll_settings_panel(
+    mut scroll_evr: MessageReader<MouseWheel>,
+    screen: Res<SettingsScreen>,
+    mut scrollables: Query<&mut ScrollPosition, With<SettingsPanelScrollable>>,
+) {
+    if !screen.0 {
+        scroll_evr.clear();
+        return;
+    }
+    let delta_y: f32 = scroll_evr
+        .read()
+        .map(|ev| match ev.unit {
+            MouseScrollUnit::Line => ev.y * 50.0,
+            MouseScrollUnit::Pixel => ev.y,
+        })
+        .sum();
+    if delta_y == 0.0 {
+        return;
+    }
+    for mut sp in scrollables.iter_mut() {
+        sp.0.y = (sp.0.y - delta_y).max(0.0);
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Window geometry persistence
+// ---------------------------------------------------------------------------